A state senator from Aurora since 2012, Oberweis made his fortune as owner of Oberweis Dairy. He’s waged a number of bids for higher office, including primary campaigns for U.S. Senate in 2002 and 2004, a 2006 bid for the GOP nomination for governor, and a campaign in the 2008 special election to replace U.S. Rep. Dennis Hastert.

He’s hoping this third bid for the U.S. Senate is the charm, and has been using a “Throwback Thursday” strategy during his campaign to compare what life was like when Durbin began his political career. Durbin, Illinois’ senior senator, has been in office since 1996 and is the Senate Majority Whip -- the second highest position in Congress’ smaller body.

"We go forward and hopefully run this campaign as fast and as hard as we can to eliminate a guy who’s compared our military to the Nazis, a guy who’s been in Washington for 32 years, which is way too long, and now he’s asking for 6 more years," Oberweis said Tuesday.

Truax, a first-time political candidate and West Point graduate from Downers Grove, conceded to Oberweis in a speech Tuesday night. He encouraged his supporters to go with Oberweis.

We've got a wonderful state and a fantastic country. So im just begging don't walk away. Stay involved.We've got to get more involved. we've got to get control before it slips away god bless this great country."

Throughout the campaign, he struggled with name recognition and lagged in the polls, despite earning the endorsement of former U.S. Rep. Newt Gingrich of Georgia.

Truax: "We've Got to Help Oberweis Beat Durbin"

Doug Truax conceded in the Republican senate primary Tuesday. It'll be Dick Durbin versus Jim Oberweis in the November election.